The new U.S. Postal Service (USPS) rules could affect whether your tax filling is considered late or filed on time. With the recent change in the postmark date system, published in November 2025 in the Federal Register, the new rule explains that a machine-applied postmark indicates the date of the "first automated processing operation" at a processing facility, which may be later than the date the mail was dropped off. 

What does this mean for you? This rule change could be problematic for tax filings, because the new USPS rules may cause your postmark to be later than the day you actually mailed your documents. If received after the IRS deadline, the document won't be considered timely filed or payment timely made unless the postmark bears a date on or before the due date (IRC Sec. 7502). The IRS will treat a tax return or payment postmarked on or before the due date as timely even if it arrives days later. 

If your postmark is dated after the deadline (even by a day) your filing will be considered late, and you could face penalties for this. 

What can you do to avoid this? If you are close to the filing deadline, do not rely on the USPS alone. To ensure your postmark date is the same as your date of mailing is, use an authorized private delivery service (UPS, FedEx, or DHL Express). If you still want to use the USPS as your method of delivery, to ensure that your postmark date is the same as the date of mailing, and have documentation to prove of it, visit the USPS counter and use one of the following: 

• Certified Mail;
• Registered Mail; or
• Postage Validation Imprint (special marking indicating postage paid and date accepted). 

The above options provide documentation proof of the mailing, which can protect you if there is ever a question about whether or not you filed timely. 

Recommended Method: File and Pay Electronically

If possible, filing your return or making a tax payment electronically is the safest way to sidestep any issues with postmarks. You receive immediate confirmation, and you don’t have to worry about postmarks or mail delays. 

However, there are a few forms that are not eligible for electronic filing (Form W-7 and Form 706). To avoid potential filing issues, it is best to visit a USPS counter for documented proof of mailing or use an authorized private delivery service that provides a tendering receipt. 

File Timely and with Ease

Each year the IRS processes between 75-90 million paper documents. While most mail is processed without issue by the USPS, delays and losses can still occur. Under the new USPS rules, the postmark may not accurately reflect the date the documents were mailed. Exercise caution for the rest of the tax filing season and wrap up 2025 by steering clear of postal penalties and future headaches.